Satellite data from ESA show that there is negligible reduction in NO2 levels in India | Photo courtesy: Ankit Kumar
The outbreak of the novel coronavirus, or Covid-19, has forced countries across the world to take extreme steps - one of these has been a complete lockdown of cities.
Both China and Italy adopted these extreme measures in order to contain the outbreak once it went out of control. While there is no conclusive way to quantify the effect of restricted human activity, its imprint on atmosphere is somewhat measurable.
Scientists have observed a pattern which links a decreased level of nitrogen dioxide (NO2), first over China and now over Italy, since the implementation of mass quarantines.
Nitrogen dioxide is usually emitted into the atmosphere as a result of human activities such as motor vehicles, power plants, and industrial facilities.
Both National Aeronautics and Space Administration (Nasa) and European Space Agency (ESA) experts link the decrease in NO2 levels with an effective decrease in machine-run activities in these areas.
WHAT ABOUT INDIA?
India has taken several steps to contain the spreading of the novel coronavirus - state governments as well as Union governments have issued multiple advisories and orders to restrict community spread, as much as possible.
Below are NO2 levels on February 7.
Below are NO2 levels on March 16,
Most administrations have ordered closing educational institutions, cinema halls and cancelled sporting events.
While there are no strict orders against domestic movements and industrial gatherings, the government has advised citizens to avoid travel and meetings.
Even Prime Minister Narendra Modi has encouraged people to work from home.
However, satellite data from the ESA show that there is negligible reduction in NO2 levels.
The data was collected between February 17 to March 16, 2020. This shows that despite all the advisories, the reduction in overall outdoor human activities in India has not been enough to leave a large imprint in the atmosphere.
This, however, may not be the exact assessment of all the activities happening on the ground, but it gives a sense of a quantifiable changes caused in the atmosphere due to large-scale human activities. Although, the situation in India is nowhere similar to that in China or Europe, these governments along with those of the UK and USA have been criticised for not taking similar measures sooner.
When it comes to the novel coronavirus outbreak, the global science community has reached a consensus that no step is enough and preemptive measures are more effective in these situations.
While experts world over are advising the governments to take more drastic measures to contain the outbreak into new areas, large-scale isolation and absence of public gatherings have shown effective results.